<template>
  <el-upload
    class="avatar-uploader"
    :show-file-list="false"
    :http-request="handleUpload"
    :before-upload="beforeAvatarUpload"
  >
    <img v-if="imageUrl" :src="imageUrl" class="avatar" />
    <el-icon v-else class="avatar-uploader-icon"><Plus /></el-icon>
  </el-upload>
</template>

<script lang="ts" setup>
import { ref } from "vue";
import { ElMessage } from "element-plus";
import { Plus } from "@element-plus/icons-vue";
import Cloud from "leancloud-storage";
import type {
  UploadProps,
  UploadRequestOptions,
  UploadFile,
} from "element-plus";

const imageUrl = ref(""); //预览图
const emit = defineEmits();
//将图片资源对象，转为base64的方法
function getBase64(
  img: Blob,
  callback: (arg: string | ArrayBuffer | null) => void
) {
  const reader = new FileReader();
  reader.addEventListener("load", () => callback(reader.result));
  reader.readAsDataURL(img);
}
//自定义图片上传逻辑函数
const handleUpload = (options: UploadRequestOptions) => {
  //   console.log(options);
  getBase64(options.file, async (base64) => {
    // console.log(base64);
    // 将base64编码发送给LeanCloud
    let res: any = await new Cloud.File("vue-admin-2304.png", {
      base64: base64,
    }).save();
    console.log(res); //res是上传成功后，后端下发的图片链接等信息
    imageUrl.value = res.attributes.url; //显示预览图
    emit("update:modelValue", res.attributes.url);
  });
};

const beforeAvatarUpload: UploadProps["beforeUpload"] = (rawFile) => {
  if (rawFile.type !== "image/jpeg" && rawFile.type !== "image/png") {
    ElMessage.error("Avatar picture must be JPG/PNG format!");
    return false;
  } else if (rawFile.size / 1024 / 1024 > 2) {
    ElMessage.error("Avatar picture size can not exceed 2MB!");
    return false;
  }
  return true;
};
</script>

<style scoped>
.avatar-uploader .avatar {
  width: 178px;
  height: 178px;
  display: block;
}
</style>

<style>
.avatar-uploader .el-upload {
  border: 1px dashed var(--el-border-color);
  border-radius: 6px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: var(--el-transition-duration-fast);
}

.avatar-uploader .el-upload:hover {
  border-color: var(--el-color-primary);
}

.el-icon.avatar-uploader-icon {
  font-size: 28px;
  color: #8c939d;
  width: 178px;
  height: 178px;
  text-align: center;
}
</style>
